<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>{% block title %}父模板{% endblock %}</title>
</head>
<body>
<div>黑马程序员</div>
{% block body %}
父模板的内容
{% endblock %}
<div>版权所有</div>
</body>
</html>

{% block xxx %}
    ......
{% endblock %}